The present invention relates to an optical waveguide module-mounted package which comprises a case and an optical waveguide module mounted in the case, the module being comprised of an optical waveguide chip and optical fibers connected to the chip. More particularly, the present invention relates to an optical waveguide module-mounted package used in the field of optical communication.
Prior Art
The recent development of optical communication technology has demanded optical waveguide module-mounted packages, such as optical branching elements and optical multiplexers, with higher cost performance and higher reliability. In general, the conventional optical waveguide module-mounted package is composed of an optical waveguide chip and optical fibers for optical input/output, connected to the terminal end surfaces of the optical waveguide chip.
When the optical waveguide module is put in use in communication system, it is generally necessary to protect the module by a package to enhance the reliability. The package provides resistance to external mechanical impact, thereby improving long-term reliability. When an optical waveguide is connected to optical fibers, a UV-setting resin is generally used as an adhesive for connection. It is known that the long-term adhesive property of the UV-setting resin is deteriorated due to intrusion of moisture. Therefore, it is of importance that the connecting portion of the optical waveguide module is protected by a case or similar means so that the connecting portion is not exposed to moisture (see Japanese Patent No. 3,070,028).
FIG. 1 shows a longitudinal cross section of a conventional optical waveguide module-mounted package, which contains an optical waveguide module comprising optical fibers 1 and an optical waveguide chip 2, connected in such manner that their axes are aligned with each other and a cylindrical case 4 in which the module is fixed via element-fixing members 3. The optical fibers 1 are fixed with optical-fiber lead-in members 5. The optical fibers 1 and the optical waveguide chip 2 are enclosed by the cylindrical case 4 and the optical-fiber lead-in members 5.
FIG. 2 shows a cross section of another conventional optical waveguide module-mounted package. An optical waveguide module comprising optical fibers 1 and an optical waveguide chip 2, connected in such manner that their axes are aligned with each other, is fixed to a lower half case 6 (the case is formed of an upper half case and a lower half case) by resin 7. The optical fibers 1 are fixed in position with optical-fiber lead-in members 5, and the optical waveguide module-mounted package is sealed with the upper half case 8 of the upper-lower separation type case. The optical fiber 1 and the optical waveguide chip 2 are enclosed by the lower half case 6 and the upper half case 8 of the upper-lower separation type case, and the optical-fiber lead-in members 5.
Problems to be Solved by the Invention
However, the structure of the conventional optical waveguide module-mounted package as shown in FIG. 1 has problems in that, in order to fix the optical waveguide module comprised of the optical waveguide chip and the optical fibers connected to the chip to the inside of the cylindrical case, it is necessary to pass the optical waveguide module through the cylindrical case and the optical fibers through the optical-fiber lead-in members. In addition, for adhesion of the optical waveguide chip to the cylindrical case via element-fixing members, special jigs are required due to the cylindrical shape. Further, the fixing portion cannot be visually checked from above the case and thus the workability becomes poor, resulting in additional working processes.
On the other hand, since the conventional optical waveguide module-mounted package shown in FIG. 2 is in the form of a box comprising an upper half and a lower half, as compared with the conventional case shown in FIG. 1, this shape allows visual checking of the portion of fixing the optical waveguide module to the case from above, and the workability is improved, leading to less working steps. However, more parts are necessary in this package, resulting in higher cost and more assembling steps, and the resultant package becomes costly.
As shown above, the conventional optical waveguide module-mounted packages have problems in that more parts are required and thus the cost for materials becomes higher; and this larger number of parts in turn requires more working processes, resulting in costly package.
The object of the present invention is to solve the above-mentioned problems by providing an optical waveguide module-mounted package in which members are integrated for the purpose of reducing the cost for materials, and the multifunction is added for the purpose of reducing the number of parts, while assemblage is still easily conducted.
Specifically, the present invention provides an optical waveguide module-mounted package containing an optical waveguide module in a separation type case, said module comprising an optical waveguide chip and a pair of optical fibers connected to said optical waveguide chip in the manner that the optical axes of said chip and said fibers are aligned with each other, wherein said separation type case is formed by combining two identical half cases, each half case being provided with a mating surface having one or more recess-protrusion pairs for fitting, said recess and said protrusion being fitted respectively over the protrusion and in the recess of the other half case.
It is preferred that each of the half cases of the above-mentioned separation type case has an optical-fiber lead-in groove at each end for leading the above-mentioned optical fibers into the case and two or more optical-fiber fixing grooves located internally of the lead-in groove for fixing the optical fibers by resin.
It is preferred that the above-mentioned separation type case have a step between the optical-fiber fixing grove and the fiber lead-in grove, so that the cross section of the optical-fiber fixing groove becomes larger than that of the fiber lead-in groove. With this structure, even when the amount of resin for fixing the optical fibers is in excess, leaking of the resin into the optical-fiber lead-in groove can be prevented. It is more preferred that the receiving recess of the optical waveguide chip be more receded or deeper, as compared with the optical-fiber fixing groove.
It is preferred that the mating surfaces of the two half cases forming the above-mentioned separation type case be adhered using a sealant, for the purpose of providing protection against ambient factors, such as moisture.
It is more preferred that the space of the above-mentioned separation type case is filled with resin for the purpose of providing further protection against ambient factors.